1. Field of the Invention
The invention relates to document information search apparatus and method for promptly searching necessary documents from a large amount of document data and to a recording medium in which a document information search program has been stored. More particularly, the invention relates to document information search apparatus and method for searching documents having similar contents by a simple operation such that a document file itself is designated as a search condition and to a recording medium in which a document information search program has been stored.
2. Description of the Related Arts
Hitherto, in a document management system using a network environment, a document information search apparatus which can search necessary documents from a large amount of document data existing on the Internet or Ethernet and can rapidly refer to it has been provided. In a document search in such a case, the user designates one or a plurality of proper words or character trains which are considered to be included in the necessary documents as keywords and searches the documents including the word(s) of the designated keyword from a search database, and a document list is displayed as a search result. In such a document information search apparatus, with respect to search target documents existing on the network, an index describing a list of important words extracted from their contents is formed for every document and stored in the search database. If a search request in which a keyword is designated is issued from the user, the index in the search database is searched, thereby outputting a search result of the document list. Further, according to the conventional document information search apparatus, after the user searched the documents which are considered to be necessary from the document list searched by the designation of the keyword, if a search of similar documents is designated with respect to the selected documents, words in which a frequency of appearance in the search documents is high are automatically extracted and added to previously executed search conditions on the basis of a condition of the OR, so that the similar documents can be searched.
However, in the case where the user wants to obtain an interesting document and search documents with contents similar to such a document via Email or the Internet, in the present situation, a word or character train included in the obtained document is selected and designated as a keyword each time and documents including the word of the designated keyword are searched from the database, thereby obtaining a document list. Subsequently, the user has to select a document from the searched document list, designate a similar document search, and search similar documents from the database. That is, even if the user desires to search similar documents of the document obtained by the Email or Internet, according to the conventional document information search apparatus, with respect to only the document which has already been registered in the search database, the similar documents can be searched by using such a registered document as a search condition, and the similar documents cannot be directly searched by using the document obtained by the user by the Email or Internet as a search condition.
When the user selects keywords which are considered to be necessary for document search from the document obtained by the Email or Internet and inputs such keywords as a search condition, if there are many keywords, it is troublesome to input them. Unless the keywords are sufficiently designated, there is a case where a search leakage occurs and an expected search result is not obtained. Further, there is also a case where the number of search documents which are obtained as a document list becomes extremely large. There is a case where it is very laborious to search necessary documents by opening documents which are considered to be concerned with target documents from the document list.